"The incident happened at around 8.20am on Wednesday May 9 in the north London area.

"The male officer is alleged to have made a racist comment in the company of other officers. One of his colleagues subsequently reported the incident to a supervisor.

"The police sergeant has been suspended from duty while inquiries continue.

"No members of the public were involved in the incident. The incident has been referred to the IPCC.

"Racism and racist language is totally unacceptable. The action taken in response to this allegation demonstrates the MPS's determination to act swiftly and to support those that challenge others when alleged racist language is used."

Last month Scotland Yard vowed to get to the bottom of "very damaging" footage of one officer apparently racially abusing a man and another allegedly assaulting a teenage boy last summer.